Endoscopic surgical procedures are routinely performed in order to accomplish various surgical tasks. In such a surgical procedure, small incisions or portals are made in the patient. An endoscope, which is a device that allows medical personnel to view the surgical site, is inserted in one of the portals. Surgical instruments used to perform other tasks are inserted into other portals. The surgeon views the surgical site through the endoscope to determine how to manipulate the surgical instruments in order to accomplish the desired procedure. An advantage of performing endoscopic surgery is that, since the portions of the body that are cut open are minimized, the portions of the body that need to heal after the surgery are likewise reduced. Moreover, during an endoscopic surgical procedure, only relatively small portions of the patient's internal organs and tissue are exposed to the open environment. This minimal opening of the patient's body lessens the extent to which a patient's organs and tissue are open to infection.
The ability to perform endoscopic surgery is enhanced by the development of powered surgical tools especially designed to perform such procedures. Once such tool is sold by the Assignee hereof under the trademark FORMULA®. This tool is in the form of a cylindrical handpiece designed to be held in the hand of the surgeon. The handpiece has a front or distal end provided with a coupling assembly for releasably holding a cutting accessory, and a motor disposed within a handpiece housing which drives the accessory. One such cutting accessory, often termed a “shaver”, includes a hub which defines the proximal end of the accessory and is appropriately configured to cooperate with the coupling assembly of the handpiece to lock the accessory thereto, an elongated and tubular housing element having a proximal end fixed to the hub, and an elongated cutting element including a drive shaft disposed within the housing element. When the accessory is attached to the handpiece, the handpiece motor couples to the drive shaft of the accessory and moves same relative to the outer housing element. The handpiece motor is selectively actuable to drive the accessory drive shaft so as to cause a desired cutting action at the distal end of the accessory. The handpiece is associated with a control unit which controls the functioning thereof, and is actuated by the user via appropriate buttons provided on the handpiece itself, or alternatively directly at the control unit.
In an endoscopic surgical procedure, irrigating fluid is introduced into the surgical site. This fluid serves as a transport media for removing tissue and debris from the surgical site. In order to remove the irrigating fluid and the material contained therein, the above handpiece and the various accessories which are usable therewith together define a suction conduit. A suction pump is connected to the handpiece to provide the suction force needed for drawing the fluid and material away from the surgical site. In order to control the suction flow through the accessory and the handpiece, the handpiece is provided with a manually operated valve which is manipulated by the surgeon to control suction of material away from the surgical site.
Mechanical cutting accessories, such as the shaver discussed above, are commonly used in arthroscopic procedures, and allow for the resection of hard and soft bodily tissues, for example, those found within the knee, shoulder and other joints. In such a cutting accessory, the outer housing element defines a window or opening at the distal end, which window is defined by an edge of the wall of the outer housing element. The cutting element drive shaft at the distal end thereof also defines a window defined by an edge of the wall of the drive shaft, and when the drive shaft is disposed within the housing element, the drive shaft window is positioned adjacent the window of the housing element. As the drive shaft is moved relative to the housing element by the handpiece motor, the cutting edge of the drive shaft window and the opposed and facing cutting edge of the housing element window cause a cutting action which effectively severs tissue located within the housing element window and between the opposed cutting edges of the housing element and drive shaft. The configurations of these opposed edges allow for removal of particular tissue types, and a variety of different blade geometries are available to specifically address the type of cutting the accessory is to carry out. For example, providing the windows of both of the housing element and drive shaft with straight cutting edges is useful for making fine or detailed cuts and removing areas of hard tissue, such as bone. Alternatively, providing the distal ends of both the housing element and drive shaft with toothed or serrated cutting edges achieves a more aggressive cut and is useful for removal of soft fibrous tissue. Thus, a surgeon may often need to switch cutting accessories during a procedure in order to carry out the appropriate type or style of cut.
While the above-described surgical accessories have proven useful, when a change in cutting is desired, these accessories require the user to remove the accessory currently in use from the patient, to remove the accessory from the handpiece, install a different accessory onto the handpiece, and then reinsert the new accessory into the surgical site. Further, the known arrangements require the purchase of a multitude of accessories, which results in higher costs and a larger number of surgical accessories which must be present in the operating room in order to carry out the desired surgical procedure.
In order to obviate or at least minimize the above disadvantages of known arrangements, the surgical accessory according to the invention combines two types of cutting styles into one accessory. Specifically, in one embodiment, the two opposite sides of the cutting window of each of the outer housing element and the cutting element drive shaft have differently-configured cutting geometries, such that each window combines two different blade styles into one window. Further, the cutting geometries of the housing element window and the cutting element drive shaft window are reversed from one another, such that the accessory will perform one cutting style in one direction of rotation of the drive shaft, for example, a “straight-on-straight” cutting style wherein the opposed cutting edges of the drive shaft window and the housing element window are both straight, and such that the accessory will perform a different cutting style in an opposite direction of rotation of the drive shaft, for example, a “tooth-on-tooth” cutting style wherein the opposed cutting edges of the drive shaft window and the housing element window are both serrated or toothed. Providing this type of blade geometry on an accessory allows the surgeon to perform two different types of cutting without having to remove the accessory from the patient and then from the handpiece, thus saving time during a procedure and reducing equipment costs.
A further embodiment of the invention also combines two types of cutting styles into one accessory. In this embodiment, a surgical accessory is provided which includes a tubular housing element in which an inner cutting element is disposed for rotation relative thereto. Further, an outer sheath is provided over the housing and cutting elements, which sheath defines an opening or window at its distal end. The housing element in this embodiment is thus an intermediate component located radially between the sheath and the cutting element. The housing element defines therein a pair of windows located on opposite sides of the distal end thereof, wherein one of these windows is configured with a first cutting style, and the opposite window is configured with a second cutting style different from the first cutting style. The cutting element located within the housing element also defines a cutting window at its distal end, which window is configured with a cutting style which in one embodiment matches the cutting style of one of the housing element windows.
The outermost sheath is movable relative to the housing and cutting elements, and can be moved by the user into a first position wherein the sheath opening is circumferentially aligned with one of the cutting windows of the housing element, or a second position wherein the sheath opening is aligned with the other or opposite cutting window of the housing element. While the first embodiment discussed above allows the surgeon to select the type of cutting style by changing the direction of rotation of the cutting element drive shaft relative to the housing element, this embodiment allows the user to rotate the outer sheath relative to the housing and cutting elements to select the type of cutting style desired.
Alternatively, the two cutting edges of the cutting window of one or both of the cutting element or housing element may be provided with different geometries as in the first embodiment, and the cutting element can be actuated in different rotational directions to provide additional or alternative cutting-style options.
Certain terminology will be used in the following description for convenience in reference only, and will not be limiting. For example, the words “upwardly”, “downwardly”, “rightwardly” and “leftwardly” will refer to directions in the drawings to which reference is made. The words “inwardly” and “outwardly” will refer to directions toward and away from, respectively, the geometric center of the arrangement and designated parts thereof. The words “forwardly” and “distally” will refer to the direction toward the end of the arrangement which is closest to the patient, and the words “rearwardly” and “proximally” will refer to the direction toward the end of the arrangement which is furthest from the patient. Said terminology will include the words specifically mentioned, derivatives thereof, and words of similar import.